Texas Winter 2019-2020

[gpsnowman]

:uarrow: Well I get up pretty early on Tuesdays so perhaps I can witness some tokenflizzardflakes. This is a new word that can be used in Scrabble by the way.

Hopefully this can come true. Not expecting anything so whatever falls is bonus coverage. Considering our recent history this is a major event!!!!

[bubba hotep]

I have to agree with FWD on this one, not really expecting anything. Models are almost always too slow with the cold air with arctic fronts. However, models, esp. the Euro, tend to linger rain back way too long and we usually dry out 3 to 6 hours before what models show in these types of setups. So with this system, temps will probably cool ahead of schedule but we will also probably dry out faster and miss the prime overlap of deeper moisture and colder air. But I will keep my fingers crossed

[bubba hotep]

12z Euro

[Ntxw]

We are overdue for an overperform surprise.

[Brent]

12z Euro

https://images.weatherbell.com/model/ecmwf-deterministic/dallas/instant_ptype/1575806400/1575990000-AHzaoBSTEuk.png

if only

I tend to agree the precip will be long gone though

[bubba hotep]

In regards to the 12z Euro, surface is warm (mid-30s) for most of the area and there is no colder air north of us to "surprise" at the surface. Then there is a warm layer at 850mb. Maybe some flakes mixing in during heavier rates but the warm surface and warm layer aloft will be hard to overcome for the DFW area.

[Brent]

In regards to the 12z Euro, surface is warm (mid-30s) for most of the area and there is no colder air north of us to "surprise" at the surface. Then there is a warm layer at 850mb. Maybe some flakes mixing in during heavier rates but the warm surface and warm layer aloft will be hard to overcome for the DFW area.

also like said earlier the NAM has zero snow

I just don't buy it happening, I could see a surprise if there was more cold air but there isn't

[hamburgerman7070]

Without a -ao and nao, it will be tough sledding, no pun intended. Perhaps that will change later. A western trough without a huge +pna is best for yall and a somewhat negative epo. Models haven't been excited about this one anyways.

[Cerlin]

Once (hoepfully) the PNA tanks, we shouldn’t have to worry about close calls like this, especially if we can get the moisture we need.

[bubba hotep]

In regards to the 12z Euro, surface is warm (mid-30s) for most of the area and there is no colder air north of us to "surprise" at the surface. Then there is a warm layer at 850mb. Maybe some flakes mixing in during heavier rates but the warm surface and warm layer aloft will be hard to overcome for the DFW area.

also like said earlier the NAM has zero snow

I just don't buy it happening, I could see a surprise if there was more cold air but there isn't

The NAMs have been surprisingly stingy with the snow for this system lol!

[Cerlin]

In regards to the 12z Euro, surface is warm (mid-30s) for most of the area and there is no colder air north of us to "surprise" at the surface. Then there is a warm layer at 850mb. Maybe some flakes mixing in during heavier rates but the warm surface and warm layer aloft will be hard to overcome for the DFW area.

also like said earlier the NAM has zero snow

I just don't buy it happening, I could see a surprise if there was more cold air but there isn't

The NAMs have been surprisingly stingy with the snow for this system lol!

I think it recognizes that the warm layers by the surface are going to be too much to overcome for snowfall.

[bubba hotep]

12z Euro EPS

[Brent]

FWD adding snow into the metro now

At the onset of precipitation Monday evening, the column
will still be relatively warm. However, over the next several
hours, forced ascent will act to cool the mid levels, while CAA
and evaporative cooling work simultaneously to send low-level
thermal profiles towards their wet bulb temperatures. By early
Tuesday morning, these mechanisms should allow the column to cool
sufficiently to allow for some snow to begin mixing with rain
across parts of North Texas. The majority of model soundings
indicate anomalously high Pacific moisture content through the mid
and upper levels, which will allow for profiles to be saturated
all the way to -20C or -30C, more than sufficient to saturate the
dendritic growth zone. The bit of uncertainty that remains is
regarding the low-level thermal profiles, particularly in the
lowest 1km, where a warm nose of +2C to +4C may still reside
through the morning hours. Despite its shallow nature, a warm nose
of +4C would likely be enough to melt most snow on its journey to
the surface. However, just a degree or two cooler and snow will
likely be able to survive the trip. Given trends towards colder
solutions in recent model runs, particularly last night`s 00z and
this morning`s 12z suites, there is a greater likelihood that
some portions of North Texas will observe a bit of snow on Tuesday
morning. In fact, it`s worth noting that all 20 GEFS members and
all 50(!) EPS members are now producing at least a small amount of
snow in some portion of our northwestern CWA during this time
period. This has increased confidence such that the mention of a
chance of snow has been expanded across North Texas (including
parts of the DFW Metroplex) with this forecast issuance.

In the "unlikely but not impossible" category: While I do not
have sleet mentioned in the worded forecast, it is possible that a
precipitation transition could consist of a brief mix of
rain/sleet before snow is observed, but rain and snow should be
the predominant 2 precipitation types. Since surface temperatures
are expected to be at or above freezing within the forecast area,
no mention of freezing rain has been included either, but there
is an outside chance that one of our far northwestern zones could
briefly dip to 31F or 30F while rain is still falling. Model-
derived precipitation types struggle mightily in these types of
scenarios with such subtleties in thermal profiles, and they have
largely been disregarded in this forecast in lieu of top-down
sounding analysis.

The bit of good news with this type of setup is that extremely
cold air is difficult to come by at the surface, and most surface
temperatures are expected to be above freezing while any snow (or
rain for that matter) would fall. This will inhibit accumulations
on roadways, especially given the fact that temperatures will
have been in the upper 60s and 70s just 12-18 hours previously.
Should a complete transition to snowfall occur and persist for a
couple of hours at any given location, then some minor
accumulations would be possible on surfaces like grass,
vehicles, and rooftops. At most, a slick spot on a bridge or two
could be a possibility, but overall, impacts from any wintry
weather should be little to none.

[Cerlin]

NAM’s trying to prove me wrong now.

Thinnest line of snow possible going through northern DFW on the 18z 12km and 3km it looks like. Doesn’t give me much confidence but nice to see it’s trying.

[bubba hotep]

18z GFS bombs Tarrant and Collin counties but skips over DFW airport.

[gpsnowman]

18z GFS bombs Tarrant and Collin counties but skips over DFW airport.

Good trend. Seems to be moving southeast bit by bit. We have a full day of models tomorrow before we all go to bed on Snow Eve. ❄ ❄ ❄

[Cerlin]

Let’s hope a southward shift is not too southward though. I’d be less surprised if cities south of the metro got snow than off DFW did at this point

[Brent]

Let’s hope a southward shift is not too southward though. I’d be less surprised if cities south of the metro got snow than off DFW did at this point

I mean, we all know recent history

I'm still not that optimistic tbh, our track record is beyond horrible lately

[Cerlin]

Let’s hope a southward shift is not too southward though. I’d be less surprised if cities south of the metro got snow than off DFW did at this point

I mean, we all know recent history

I'm still not that optimistic tbh, our track record is beyond horrible lately

Agreed. I’ve yet to track a system that actually produced something for DFW since I got into weather.

[bubba hotep]

Happy Hour GEFS hitting the sauce pretty hard and showing a mean of nearly 3" at DFW lol